Priabonian
Encyclopedia
The Priabonian is, in the ICS
International Commission on Stratigraphy
The International Commission on Stratigraphy , sometimes referred to by the unofficial "International Stratigraphic Commission" is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigraphy, geological, and geochronological matters on a global...

's geologic timescale, the latest age or the upper stage of the Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...

 epoch
Epoch (geology)
An epoch is a subdivision of the geologic timescale based on rock layering. In order, the higher subdivisions are periods, eras and eons. We are currently living in the Holocene epoch...

 or series
Series (stratigraphy)
Series are subdivisions of rock layers made based on the age of the rock and corresponding to the dating system unit called an epoch, both being formally defined international conventions of the geological timescale. A series is therefore a sequence of rock depositions defining a...

. It spans the time between and . The Priabonian is preceded by the Bartonian
Bartonian
The Bartonian is, in the ICS's geological timescale, a stage or age in the middle Eocene epoch or series. The Bartonian age spans the time between and . It is preceded by the Lutetian and is followed by the Priabonian age.-Stratigraphic definition:...

 and is followed by the Rupelian
Rupelian
The Rupelian is, in the geologic timescale, the older of two ages or the lower of two stages of the Oligocene epoch/series. It spans the time between and . It is preceded by the Priabonian stage and is followed by the Chattian stage....

, the lowest stage of the Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...

.

Stratigraphic definition

The Priabonian stage was introduced in scientific literature by Ernest Munier-Chalmas and Albert de Lapparent in 1893. The stage is named afted the small hamlet of Priabona in the community of Monte di Malo
Monte di Malo
Monte di Malo is a town in the province of Vicenza, Veneto, Italy. It is west of SP46. As of 2007 Monte di Malo had an estimated population of 3,021.-Sources:*...

, in the Veneto
Veneto
Veneto is one of the 20 regions of Italy. Its population is about 5 million, ranking 5th in Italy.Veneto had been for more than a millennium an independent state, the Republic of Venice, until it was eventually annexed by Italy in 1866 after brief Austrian and French rule...

 region of northern Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

.

The base of the Priabonian stage is at the first appearance of calcareous nannoplankton species Chiasmolithus oamaruensis (which forms the base of nannoplankton biozone
Biozone
Biostratigraphic units or Biozones are intervals of geological strata that are defined on the basis of their characteristic fossil taxa....

 NP18). An official GSSP had in 2009 not yet been assigned.

The top of the Priabonian stage (the base of the Rupelian stage and Oligocene series) is at the extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...

 of foram genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Hantkenina.

Sometimes local rock strata cannot be correlated in sufficient detail with the ICS timescale, and stratigraphers often use regional timescales as alternatives to the ICS timescale. The Priabonian overlaps for example the upper Johannian and lower Aldingan stages of the Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

n timescale or the upper Nanzian and lower Refugian stages of the California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

n timescale. Other regional stages which are more or less coeval with the Priabonian include the Jacksonian of the southeastern US and Runangan of New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

.

In biostratigraphy
Biostratigraphy
Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them. Usually the aim is correlation, demonstrating that a particular horizon in one geological section represents the same period...

, the Priabonian stage is coeval with the Chadronian
Chadronian
The Chadronian age within the North American Land Mammal Ages chronology is the North American faunal stage typically set from 38,000,000 to 33,900,000 years BP, a period of . It is usually considered to fall within the Eocene epoch...

 North American Land Mammal Age, the Headonian European Land Mammal Mega Zone (in more detail: with the Mammal Paleogene zones 17A through 20), parts of the Barrancan and Mustersan
Mustersan
The Mustersan age is a period of geologic time within the Eocene epoch of the Paleogene used more specifically with South American Land Mammal Ages. It follows the Casamayoran and precedes the Divisaderan age....

 South American Land Mammal Ages and the Ulangochuian
Ulangochuian
The Ulangochuian age is a period of geologic time within the Late Eocene epoch of the Paleogene used more specifically with Asian Land Mammal Ages. It follows the Sharamurunian and precedes the Ergilian age....

 and Ergilian
Ergilian
The Ergilian age is a period of geologic time within the Late Eocene epoch of the Paleogene used more specifically with Asian Land Mammal Ages. It follows the Ulangochuian and precedes the Houldjinian age....

 Asian Land Mammal Ages
Asian land mammal ages
The Asian Land Mammal Ages establishes a geologic timescale for prehistoric Asian fauna beginning 58.7 Mya during the Paleogene and continuing through to the Middle Pleistocene...

.

Literature

; 2004: A Geologic Time Scale 2004, Cambridge University Press
Cambridge University Press
Cambridge University Press is the publishing business of the University of Cambridge. Granted letters patent by Henry VIII in 1534, it is the world's oldest publishing house, and the second largest university press in the world...

.; 1893: Note sur la nomenclature des terrains sédimentaires, Bulletin de la Societé Géologique de France 3(21), p. 479-480.

External links

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